General G6A: Batteries and components
These are the 12 official questions in group G6A of the 2023–2027 General question pool, with the correct answer marked and a plain-English explanation of why it's right. The real exam asks one question from this group.
- G6A01Question 1
What is the minimum allowable discharge voltage for maximum life of a standard 12-volt lead-acid battery?
- A6 volts
- B8.5 volts
- C10.5 volts Correct
- D12 volts
Why: Discharging a 12 V lead-acid battery below about 10.5 V shortens its life.
- G6A02Question 2
What is an advantage of batteries with low internal resistance?
- ALong life
- BHigh discharge current Correct
- CHigh voltage
- DRapid recharge
Why: Low internal resistance lets a battery deliver high current.
- G6A03Question 3
What is the approximate forward threshold voltage of a germanium diode?
- A0.1 volt
- B0.3 volts Correct
- C0.7 volts
- D1.0 volts
Why: A germanium diode starts conducting at about 0.3 V.
- G6A04Question 4
Which of the following is characteristic of an electrolytic capacitor?
- ATight tolerance
- BMuch less leakage than any other type
- CHigh capacitance for a given volume Correct
- DInexpensive RF capacitor
Why: Electrolytic capacitors offer high capacitance for their size.
- G6A05Question 5
What is the approximate forward threshold voltage of a silicon junction diode?
- A0.1 volt
- B0.3 volts
- C0.7 volts Correct
- D1.0 volts
Why: A silicon diode starts conducting at about 0.7 V.
- G6A06Question 6
Why should wire-wound resistors not be used in RF circuits?
- AThe resistor’s tolerance value would not be adequate
- BThe resistor’s inductance could make circuit performance unpredictable Correct
- CThe resistor could overheat
- DThe resistor’s internal capacitance would detune the circuit
Why: A wire-wound resistor's inductance can make RF circuits behave unpredictably.
- G6A07Question 7
What are the operating points for a bipolar transistor used as a switch?
- ASaturation and cutoff Correct
- BThe active region (between cutoff and saturation)
- CPeak and valley current points
- DEnhancement and depletion modes
Why: A transistor switch runs between saturation (on) and cutoff (off).
- G6A08Question 8
Which of the following is characteristic of low voltage ceramic capacitors?
- ATight tolerance
- BHigh stability
- CHigh capacitance for given volume
- DComparatively low cost Correct
Why: Low-voltage ceramic capacitors are comparatively inexpensive.
- G6A09Question 9
Which of the following describes MOSFET construction?
- AThe gate is formed by a back-biased junction
- BThe gate is separated from the channel by a thin insulating layer Correct
- CThe source is separated from the drain by a thin insulating layer
- DThe source is formed by depositing metal on silicon
Why: A MOSFET's gate is insulated from the channel by a thin layer.
- G6A10Question 10
Which element of a vacuum tube regulates the flow of electrons between cathode and plate?
- AControl grid Correct
- BSuppressor grid
- CScreen grid
- DTrigger electrode
Why: The control grid regulates electron flow from cathode to plate.
- G6A11Question 11
What happens when an inductor is operated above its self-resonant frequency?
- AIts reactance increases
- BHarmonics are generated
- CIt becomes capacitive Correct
- DCatastrophic failure is likely
Why: Above its self-resonant frequency, an inductor behaves like a capacitor.
- G6A12Question 12
What is the primary purpose of a screen grid in a vacuum tube?
- ATo reduce grid-to-plate capacitance Correct
- BTo increase efficiency
- CTo increase the control grid resistance
- DTo decrease plate resistance
Why: The screen grid reduces capacitance between the grid and the plate.